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Frontiers in Immunology 2023The Gram-negative bacterium is the causal agent of furunculosis and used to be one of the most loss-causing bacterial infections in the salmonid aquaculture industry...
The Gram-negative bacterium is the causal agent of furunculosis and used to be one of the most loss-causing bacterial infections in the salmonid aquaculture industry with a mortality rate of about 90% until the 1990s, when an inactivated vaccine with mineral oil as adjuvant was successfully implemented to control the disease. However, the use of this vaccine is associated with inflammatory side effects in the peritoneal cavity as well as autoimmune reactions in Atlantic salmon, and incomplete protection has been reported in rainbow trout. We here aimed at developing and testing a recombinant alternative vaccine based on virus-like particles (VLPs) decorated with VapA, the key structural surface protein in the outer A-layer of . The VLP carrier was based on either the capsid protein of a fish nodavirus, namely red grouper nervous necrotic virus (RGNNV) or the capsid protein of AP205. The VapA and capsid proteins were expressed individually in and VapA was fused to auto-assembled VLPs using the SpyTag/SpyCatcher technology. Rainbow trout were vaccinated/immunized with the VapA-VLP vaccines by intraperitoneal injection and were challenged with 7 weeks later. The VLP vaccines provided protection comparable to that of a bacterin-based vaccine and antibody response analysis demonstrated that vaccinated fish mounted a strong VapA-specific antibody response. To our knowledge, this is the first demonstration of the potential use of antigen-decorated VLPs for vaccination against a bacterial disease in salmonids.
Topics: Animals; Aeromonas salmonicida; Oncorhynchus mykiss; Capsid Proteins; Escherichia coli; Vaccination; Vaccines, Synthetic
PubMed: 37283749
DOI: 10.3389/fimmu.2023.1139206 -
RNA (New York, N.Y.) Sep 2023Unique chemical and physical properties are introduced by inserting selenocysteine (Sec) at specific sites within proteins. Recombinant and facile production of...
Unique chemical and physical properties are introduced by inserting selenocysteine (Sec) at specific sites within proteins. Recombinant and facile production of eukaryotic selenoproteins would benefit from a yeast expression system; however, the selenoprotein biosynthetic pathway was lost in the evolution of the kingdom Fungi as it diverged from its eukaryotic relatives. Based on our previous development of efficient selenoprotein production in bacteria, we designed a novel Sec biosynthesis pathway in using translation components. tRNA was mutated to resemble tRNA to allow recognition by seryl-tRNA synthetase as well as selenocysteine synthase (SelA) and selenophosphate synthetase (SelD). Expression of these Sec pathway components was then combined with metabolic engineering of yeast to enable the production of active methionine sulfate reductase enzyme containing genetically encoded Sec. Our report is the first demonstration that yeast is capable of selenoprotein production by site-specific incorporation of Sec.
Topics: Codon, Terminator; Saccharomyces cerevisiae; Aeromonas salmonicida; Protein Engineering; RNA, Transfer, Cys; Humans; Nucleic Acid Conformation
PubMed: 37279998
DOI: 10.1261/rna.079658.123 -
Fish & Shellfish Immunology Aug 2023The Yellow River carp (Cyprinus carpio haematopterus) is a vital economically farmed fish of the Cyprinidae family. With the development of intensive aquaculture, carp...
The Yellow River carp (Cyprinus carpio haematopterus) is a vital economically farmed fish of the Cyprinidae family. With the development of intensive aquaculture, carp production has increased dramatically, leading to the frequent occurrence of various diseases. Cell lines are considered the most cost-effective resource for in vitro studies and are widely used for physiological and pathological studies because of accessibility and convenience. This research established a novel immortal cell line CCM (Yellow River carp muscle cells) derived from the carp muscle. CCM has been passed over 71 generations for 1 year. The morphology of CCM and the adhesion and extension processes were captured by light and electron microscopy. CCM were passaged every 3 days with 20% FBS DMEM/F12 at 1:3. The optimum conditions for CCM growth were 28 °C and 20% FBS concentration. DNA sequencing of 16S rRNA and COI showed that CCM was derived from carp. CCM positively reacts to anti-PAX7 and anti-MyoD antibodies of carp. Analysis of chromosomes revealed that the chromosomal pattern number of CCM was 100. Transfection experiment demonstrated that CCM might be utilized to express foreign genes. Furthermore, cytotoxicity testing showed that CCM was susceptible to Aeromonas hydrophila, Aeromonas salmonicida, Aeromonas veronii, and Staphylococcus Aureus. The organophosphate pesticides (chlorpyrifos and glyphosate) or heavy metals (Hg, Cd, and Cu) exhibited dose-dependent cytotoxicity against CCM. After LPS treatment, the MyD88-IRAKs-NFκB pathway stimulates inflammatory-related factor il1β, il8, il10, and nfκb expression. LPS did not seem to cause oxidative stress in CCM, and the expression of cat and sod was not affected. Poly (I:C) through TLR3-TRIF-MyD88-TRAF6-NFκB and TRIF-TRAF3-TBK1-IRF3 activated the transcription of related factors, increased expression of anti-viral protein, but no changes in apoptosis-related genes. To our knowledge, this is the first muscle cell line in Yellow River carp and the first study on the immune response signal pathways of Yellow River carp based on the muscle cell line. CCM cell line provides a more rapid and efficient experimental material for fish immunology research, and this study preliminarily elucidated its immune response strategy to LPS and poly (I:C).
Topics: Animals; Carps; RNA, Ribosomal, 16S; Lipopolysaccharides; Myeloid Differentiation Factor 88; Poly I-C; Muscles; Muscle Cells; Cell Line; Adaptor Proteins, Vesicular Transport; Fish Diseases
PubMed: 37277052
DOI: 10.1016/j.fsi.2023.108859 -
Fish & Shellfish Immunology Aug 2023In recent years, more than one pathogenic organism has usually been isolated from diseased turbot Scophthalmus maximus, creating a pressing need for the development of...
In recent years, more than one pathogenic organism has usually been isolated from diseased turbot Scophthalmus maximus, creating a pressing need for the development of combination vaccines to prevent fish diseases brought on simultaneously by various infections. In this study, the inactivated bivalent vaccine of Aeromonas salmonicida and Edwardsiella tarda was prepared by the formalin inactivation method. After challenge with A. salmonicida and E. tarda at 4 weeks post-vaccination in turbot, the relative percentage survival (RPS) of the inactivated bivalent vaccine was 77.1%. In addition, we assessed the effects of the inactivated bivalent vaccine and evaluated the immunological processes after immunization in a turbot model. Serum antibody titer and lysozyme activity of the vaccinated group were both upregulated and higher than that in control group after vaccination. The expression levels of genes (TLR2, IL-1β, CD4, MHCI, MHCⅡ) that related to antigen recognition, processing and presentation were also studied in the liver, spleen and kidney tissues of vaccinated turbot. All the detected genes in the vaccinated group had a significant upward trend, and most of them reached the maximum value at 3-4 weeks, which had significant differences from the control group, suggesting that antigen recognition, processing and presentation pathway was activated by the inactivated bivalent vaccine. Our study provides a basis for further application of the killed bivalent vaccine against A. salmonicida and E. tarda in turbot, making it good potential that can be applied in aquaculture.
Topics: Animals; Enterobacteriaceae Infections; Edwardsiella tarda; Aeromonas salmonicida; Flatfishes; Antibodies, Bacterial; Vaccines, Combined; Fish Diseases; Bacterial Vaccines
PubMed: 37269913
DOI: 10.1016/j.fsi.2023.108837 -
Marine Drugs Apr 2023Exploration of seaweeds to unravel their bioactive metabolites from the perspective of wider applications gained substantial importance. The present study was performed...
Exploration of seaweeds to unravel their bioactive metabolites from the perspective of wider applications gained substantial importance. The present study was performed to investigate the total phenolic, flavonoid, tannin content, antioxidant activity and antibacterial potential of various solvent extracts of green seaweed . The methanolic extract showed higher phenolic (11.99 ± 0.48 mg gallic acid equivalents/g), tannin (18.59 ± 0.54 mg tannic acid equivalents/g) and flavonoid (33.17 ± 0.76 mg quercetin equivalents/g) content than other extracts. Antioxidant activity was determined by using 2,2-diphenylpicrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay with different concentrations of extracts. The methanolic extract showed higher scavenging potential in both the DPPH and ABTS activity with the inhibition value of 54.21 ± 1.39% and 76.62 ± 1.08%, respectively. Bioactive profiling was also identified by using Gas chromatography-mass spectrometry (GC-MS) and Fourier transform infrared (FT-IR) techniques. These studies revealed the presence of valuable bioactive compounds in extracts and these compounds might be responsible for antimicrobial, antioxidant, anticancer and anti-mutagenic properties. Major compounds identified in GC-MS were 3,7,11,15-Tetramethyl-2-hexadecen-1-ol, 3-hexadecene and Phthalic acid. In terms of antibacterial activity, has promising antibacterial potential against aquatic pathogens and . Further evaluation studies focusing aquatic related aspects would reveal the novel bioproperties and applications of .
Topics: Antioxidants; Gas Chromatography-Mass Spectrometry; Caulerpa; Seaweed; Spectroscopy, Fourier Transform Infrared; Plant Extracts; Anti-Bacterial Agents; Flavonoids; Phenols; Phytochemicals; Tannins
PubMed: 37233472
DOI: 10.3390/md21050278 -
Food Chemistry Oct 2023Microbial spoilage of meat products is a significant problem in the food industry. Aeromonas salmonicida is a significant microorganism responsible for spoilage in...
The interaction of an effector protein Hap secreted by Aeromonas salmonicida and myofibrillar protein of meat: Possible mechanisms from structural changes to sites of molecular docking.
Microbial spoilage of meat products is a significant problem in the food industry. Aeromonas salmonicida is a significant microorganism responsible for spoilage in chilled meat. Its effector protein, hemagglutinin protease (Hap), has been identified as an effective substance for degrading meat proteins. The ability of Hap to hydrolyze myofibrillar proteins (MPs) in vitro demonstrated that Hap has obvious proteolytic activity, which could alter MPs' tertiary structure, secondary structure, and sulfhydryl groups. Moreover, Hap could significantly degrade MPs, focusing primarily on myosin heavy chain (MHC) and actin. Active site analysis and molecular docking revealed that the active center of Hap was bound to MPs via hydrophobic interaction and hydrogen bonding. It may preferentially cleave peptide bonds between Gly44-Val45 in actin, and Ala825-Phe826 in MHC. These findings suggest that Hap may be involved in the spoilage mechanism of microorganisms and provide crucial insights into the mechanisms of meat spoilage induced by bacteria.
Topics: Aeromonas salmonicida; Molecular Docking Simulation; Actins; Meat; Proteolysis; Myosin Heavy Chains
PubMed: 37207606
DOI: 10.1016/j.foodchem.2023.136365 -
Applied Biochemistry and Biotechnology Feb 2024Aloe barbadensis Miller (ABM) is a traditional medicinal plant all over the world. Numerous studies were conducted to exhibit its medicinal properties and most of them...
Bioactive Analysis of Antibacterial Efficacy and Antioxidant Potential of Aloe barbadensis Miller Leaf Extracts and Exploration of Secondary Metabolites Using GC-MS Profiling.
Aloe barbadensis Miller (ABM) is a traditional medicinal plant all over the world. Numerous studies were conducted to exhibit its medicinal properties and most of them were concentrated on its metabolites against human pathogens. The current research work evaluates the attributes of different polar-based extracts (ethanol, methanol, ethyl acetate, acetone, hexane, and petroleum ether) of dried Aloe barbadensis leaf (ABL) to investigate its phytochemical constituents, antioxidant potential (DPPH, ABTS), phenolic, tannin, flavonoid contents, identification of bioactive compounds, and functional groups by gas chromatography-mass spectrometry (GC-MS) and fourier transform infrared spectroscopy (FT-IR) respectively, and comparing antibacterial efficacy against human pathogens, aquatic bacterial pathogens, and zoonotic bacteria associated with fish and human. The present results showed that the methanolic extract of ABL showed higher antioxidant activity (DPPH-59.73 ± 2.01%; ABTS-74.1 ± 1.29%), total phenolic (10.660 ± 1.242 mg GAE/g), tannin (7.158 ± 0.668 mg TAE/g), and flavonoid content (49.545 ± 1.928 µg QE/g) than that of other solvent extracts. Non-polar solvents hexane and petroleum ether exhibited lesser activity among the extracts. In the case of antibacterial activity, higher inhibition zone was recorded in methanol extract of ABL (25.00 ± 0.70 mm) against Aeromonas salmonicida. Variations in antibacterial activity were observed depending on solvents and extracts. In the current study, polar solvents revealed higher antibacterial activity when compared to the non-polar and the mid-polar solvents. Diverse crucial bioactive compounds were detected in GC-MS analysis. The vital compounds were hexadecanoic acid (30.69%) and 2-pentanone, 4-hydroxy-4-methyl (23.77%) which are responsible for higher antioxidant and antibacterial activity. Similar functional groups were identified in all the solvent extracts of ABL with slight variations in the FT-IR analysis. Polar-based solvent extraction influenced the elution of phytocompounds more than that of the other solvents used in this study. The obtained results suggested that the ABM could be an excellent source for antioxidant and antibacterial activities and can also serve as a potential source of effective bioactive compounds to combat human as well as aquatic pathogens.
Topics: Animals; Humans; Antioxidants; Tannins; Plant Extracts; Gas Chromatography-Mass Spectrometry; Aloe; Hexanes; Methanol; Spectroscopy, Fourier Transform Infrared; Anti-Bacterial Agents; Solvents; Phytochemicals; Flavonoids; Alkanes; Sulfonic Acids; Benzothiazoles
PubMed: 37184725
DOI: 10.1007/s12010-023-04565-z -
Applied Biochemistry and Biotechnology Jan 2024Nyctanthes arbor-tristis, alias "Vishnu Parijat," is a medicinal plant used to treat various inflammation-associated ailments and to combat innumerable infections in the...
Nyctanthes arbor-tristis, alias "Vishnu Parijat," is a medicinal plant used to treat various inflammation-associated ailments and to combat innumerable infections in the traditional system of medicine. In the present study, we collected the samples of N. arbor-tristis from the lower Himalayan region of Uttarakhand, India, and carried out their molecular identification through DNA barcoding. To examine the antioxidant and antibacterial activities, we prepared the ethanolic and aqueous extracts (from flowers and leaves) and performed their phytochemical analysis by using different qualitative and quantitative approaches. The phytoextracts showed marked antioxidant potential, as revealed by a comprehensive set of assays. The ethanolic leaf extract showed marked antioxidant potential towards DPPH, ABTS, and NO scavenging (IC = 30.75 ± 0.006, 30.83 ± 0.002, and 51.23 ± 0.009 μg/mL, respectively). We used TLC-bioautography assay to characterize different antioxidant constituents (based on their Rf values) in the chromatograms ran under different mobile phases. For one of the prominent antioxidant spots in TLC bioautography, GC-MS analysis identified cis-9-hexadecenal and n-hexadecanoic acid as the major constituents. Furthermore, in antibacterial study, the ethanolic leaf extract showed marked activity against Aeromonas salmonicida (113.40 mg/mL of extract was equivalent to 100 μg/mL of kanamycin). In contrast, the ethanolic flower extract showed considerable antibacterial activity against Pseudomonas aeruginosa (125.85 mg/mL of extract ≡100 μg/mL of kanamycin). This study presents the phylogenetic account and unravels the antioxidant-related properties and antibacterial potential of N. arbor-tristis.
Topics: Plant Extracts; Antioxidants; Phylogeny; Anti-Bacterial Agents; Kanamycin; Oleaceae; Phytochemicals; Plant Leaves
PubMed: 37140779
DOI: 10.1007/s12010-023-04552-4 -
Iranian Journal of Microbiology Jun 2022Melioidosis is an emerging infection, a potentially fatal tropical disease caused by in humans and animals, endemic in Southeast Asia and northern Australia. Diagnosis...
Melioidosis is an emerging infection, a potentially fatal tropical disease caused by in humans and animals, endemic in Southeast Asia and northern Australia. Diagnosis remains problematic due to its similarity to many other infections. The lack of clinical awareness and correct microbiological diagnosis contributes to the misidentification of melioidosis. We present a melioidosis case, which was misdiagnosed with pneumonia and septicemia due to , leading to ineffective prolonged-course antibiotic treatment for the patient.
PubMed: 37124859
DOI: 10.18502/ijm.v14i3.9796 -
Frontiers in Veterinary Science 2023Psychrophilic could not grow above 25°C and therefore thought unable to infect mammals and humans. In our previous study, a mesophilic SRW-OG1 was isolated from with...
Psychrophilic could not grow above 25°C and therefore thought unable to infect mammals and humans. In our previous study, a mesophilic SRW-OG1 was isolated from with furunculosis. Through the analysis of preliminary RNA-seq, it was found that the Zn uptake related genes and might be involved in the virulence regulation of SRW-OG1. Therefore, the purpose of this study was to explore the effect of silencing on the virulence regulation of SRW-OG1. The results showed that the growth of the -RNAi, -RNAi, and -RNAi strains was severely restricted under the Fe starvation, but surprisingly there was no significant difference under the Zn restriction. In the absence of Zn and Fe, the expression level of was significantly increased. The motility, biofilm formation, adhesion and hemolysis of the -RNAi, -RNAi, and -RNAi strains were significantly reduced. We also detected the expression of under different growth periods, temperatures, pH, as well as Cu and Pb stresses. The results showed that was significantly up-regulated in the logarithmic phase and the decline phase of . Interestingly, the trend of expression levels of the at 18, 28, and 37°C was reversed to another Zn uptake related gene . Taken together, these indicated that the was necessary for SRW-OG1 pathogenicity and environmental adaptability, and was cross regulated by iron starvation, but it was not irreplaceable for SRW-OG1 Zn uptake in the host.
PubMed: 37065252
DOI: 10.3389/fvets.2023.1172123